This grant represents an attempt to understand in a systematic way, the various hormones and growth factors which control the growth and metabolism of lens cells in culture. The specific aims of the research are: 1) To study external signals that modify lens cell proliferation; 2) To obtain information on the nature of surface receptors on lens cells; 3) To investigate the primary biological response elicited by growth factors; 4) To look at possible models for the transfer of information across the cell membrane; 5) The use of genetics to approach the mechanism of action of growth factors. It is felt that this molecular approach to growth regulation using defined external signals should yield important information on the problem of cataractogenesis.